It is good practice to supply a written report to the buyer.

向买主提供书面报告是诚信的做法。

In theory, the buyer could ask the seller to have a test carried out.

在理论上，买方可以要求卖方进行一次产品检测。

The selling broker is then required to assign a portion of the commission to the buyer broker.

卖方经纪人则被要求分给买方经纪人一部分佣金。

I think the moral of the story is let the buyer beware.

我想这个故事的寓意是提醒购买者当心。

The buyer has to sign a delivery note as proof of receipt.

购买者必须签收送货单表明货已收到。